RenderWindow does not close with vtk-9.0.0 on Ubuntu 18.04

Hello,

The render window does not close out when running the following with Python 3.7.7 using the wheel vtk-9.0.0-cp37-cp37m-linux_x86_64.whl on Ubuntu 18.04.

import vtk

arrowSource = vtk.vtkArrowSource()

mapper = vtk.vtkPolyDataMapper()
mapper.SetInputConnection(arrowSource.GetOutputPort())
actor = vtk.vtkActor()
actor.SetMapper(mapper)

renderer = vtk.vtkRenderer()
renderer.AddActor(actor)

renderWindow = vtk.vtkRenderWindow()
renderWindow.SetWindowName("Arrow")
renderWindow.AddRenderer(renderer)

renderWindowInteractor = vtk.vtkRenderWindowInteractor()
renderWindowInteractor.SetRenderWindow(renderWindow)
renderWindowInteractor.Start()

renderWindow.Finalize()
del renderWindowInteractor, renderWindow

Render window also fails to close when using conda-forge/linux-64::vtk-9.0.0-no_osmesa_py38hc86227b_100 on Python 3.8.3 on anaconda on Ubuntu 18.04

The render window closes correctly on Mac OS with vtk 9.0.0, and Linux with vtk==8.1.2.

Thanks for your hard work getting this last release out!